ICBDSR Report 2024

France REMERA, 2015 to 2020

  • total births in the 6-year period: 337,271 (livebirths: 333,632)
  • average births per year: 56,210 (livebirths: 55,610)
  • terminations of pregnancy legal in country: Yes
  • data include terminations of pregnancy: Yes
  • source structure: Population-based

Country where the program is located

A word from the program

The registry is population based. Terminations are registered since 1985 (TOP can be performed up to full term in case of lethal or severe foetal abnormalities).


Selected data highlights

The following tables highlight selected sets of congenital anomalies, each with a specific focus.

Top Ten

Here are the program’s top ten conditions by frequency, selected among those with significant clinical and public health impact. These are the conditions that one is more likely to encounter in the population under surveillance and impact the largest number of individuals and their families.

Top 10 Conditions by Frequency

among specific diagnoses with major health impact, France REMERA, 2015-2020
shown are total cases for the reporting period, yearly average cases, and prevalence per 10,000

Condition Cases Yearly Avg Prevalence
Down syndrome 915 152 27.1
Cystic kidney 376 63 11.1
Cleft lip with or without cleft palate 287 48 8.5
Trisomy 18 247 41 7.3
Hydrocephaly 232 39 6.9
Cleft palate without cleft lip 232 39 6.9
Spina bifida 205 34 6.1
Anencephaly 153 26 4.5
Transposition of great vessels 149 25 4.4
Omphalocele 143 24 4.2

Notable Seven

These conditions exemplify the impact of congenital anomalies on morbidity and mortality. For example, neural tube defects and critical congenital heart disease, when combined, account for approximately half of all infant deaths associated with congenital anomalies.

For several of these conditions, modifiable risk factors are well established, and primary prevention, if implemented appropriately, works. This implication is unpacked in a later section (‘what if scenario’).

Seven highly impactful conditions

selected on the basis of high morbidity and mortality, and potential for primary prevention
France REMERA, 2015-2020

Yearly cases

Percent
liveborn

Prevalence
per 10,000

Program

Country

Neural tube defects (NTD)
Neural tube defects, total 70 901 18 12.5
Spina bifida 34 440 25 6.1
Anencephaly 26 324 3 4.5
Orofacial
Cleft lip with or without cleft palate 48 612 78 8.5
Cleft palate without cleft lip 39 497 78 6.9
Heart
Transposition of great vessels 25 317 78 4.4
Hypoplastic left heart syndrome 19 245 33 3.4
Tetralogy of Fallot 18 238 69 3.3
Estimated from program prevalence extrapolated to total country births. France births for 2022 from World Bank

The full table

This more expansive set of major congenital anomalies, internal and external, includes most conditions of significant clinical and public health impact. A more detailed view of Trisomy 21 (Down syndrome) is included in a later section. Note: a child with multiple anomalies will be counted in all pertinent rows.

Selected congenital conditions by system

number of cases and prevalence (prev) per 10,000, for all births and livebirths
France REMERA, 2015-2020

All births Livebirths
Cases Prev 95% CI Cases Prev 95% CI
Neural tube defects (NTD)
Neural tube defects, total 422 12.5 11.3 - 13.8 74 2.2 1.7 - 2.7
Spina bifida 205 6.1 5.3 - 7.0 51 1.5 1.1 - 1.9
Anencephaly 153 4.5 3.8 - 5.3 5 0.1 0.0 - 0.3
Encephalocele 64 1.9 1.5 - 2.4 18 0.5 0.3 - 0.8
Other brain
Hydrocephaly 232 6.9 6.0 - 7.8 120 3.6 3.0 - 4.2
Microcephaly 78 2.3 1.8 - 2.9 52 1.6 1.1 - 2.0
Holoprosencephaly 72 2.1 1.7 - 2.7 5 0.1 0.0 - 0.3
Eye and Ear
Microphthalmos 61 1.8 1.4 - 2.3 38 1.1 0.8 - 1.5
Anotia 41 1.2 0.9 - 1.6 35 1.0 0.7 - 1.4
Microtia 32 0.9 0.6 - 1.3 27 0.8 0.5 - 1.1
Anophthalmos 5 0.1 0.0 - 0.3 1 0.0 0.0 - 0.2
Orofacial
Cleft lip with or without cleft palate 287 8.5 7.6 - 9.6 224 6.7 5.8 - 7.6
Cleft palate without cleft lip 232 6.9 6.0 - 7.8 182 5.5 4.7 - 6.2
Choanal atresia bilateral 23 0.7 0.4 - 1.0 20 0.6 0.3 - 0.9
Heart
Transposition of great vessels 149 4.4 3.7 - 5.2 116 3.5 2.8 - 4.1
Coarctation of aorta 119 3.5 2.9 - 4.2 112 3.4 2.7 - 4.0
Hypoplastic left heart syndrome 113 3.4 2.8 - 4.0 37 1.1 0.8 - 1.5
Tetralogy of Fallot 111 3.3 2.7 - 4.0 77 2.3 1.8 - 2.8
Gastrointestinal
Anorectal atresia/stenosis 120 3.6 2.9 - 4.3 82 2.5 1.9 - 3.0
Esophageal atresia 103 3.1 2.5 - 3.7 88 2.6 2.1 - 3.2
Small intestinal atresia/stenosis 33 1.0 0.7 - 1.4 29 0.9 0.6 - 1.2
Genitourinary
Undescended testis 687 20.4 18.9 - 22.0 687 20.6 19.1 - 22.1
Cystic kidney 376 11.1 10.0 - 12.3 263 7.9 6.9 - 8.8
Hypospadias 361 10.7 9.6 - 11.9 350 10.5 9.4 - 11.6
Renal agenesis 40 1.2 0.8 - 1.6 15 0.4 0.2 - 0.7
Indeterminate sex 11 0.3 0.2 - 0.6 8 0.2 0.1 - 0.4
Bladder exstrophy 10 0.3 0.1 - 0.5 2 0.1 0.0 - 0.2
Epispadias 7 0.2 0.1 - 0.4 7 0.2 0.1 - 0.4
Limb
Limb deficiency (LD), total 244 7.2 6.4 - 8.2 159 4.8 4.0 - 5.5
Polydactyly preaxial 112 3.3 2.7 - 4.0 106 3.2 2.6 - 3.8
LD transverse 84 2.5 2.0 - 3.1 52 1.6 1.1 - 2.0
LD postaxial 51 1.5 1.1 - 2.0 35 1.0 0.7 - 1.4
LD preaxial 39 1.2 0.8 - 1.6 27 0.8 0.5 - 1.1
LD axial 27 0.8 0.5 - 1.2 22 0.7 0.4 - 0.9
LD mixed 25 0.7 0.5 - 1.1 11 0.3 0.1 - 0.5
LD intercalary 12 0.4 0.2 - 0.6 10 0.3 0.1 - 0.5
LD unspec. 6 0.2 0.1 - 0.4 2 0.1 0.0 - 0.2
Abdominal
Omphalocele 143 4.2 3.6 - 5.0 45 1.3 1.0 - 1.7
Diaphragmatic hernia 115 3.4 2.8 - 4.1 77 2.3 1.8 - 2.8
Gastroschisis 57 1.7 1.3 - 2.2 49 1.5 1.1 - 1.9
Prune belly sequence 2 0.1 0.0 - 0.2 0 0.0 0.0 - 0.1
Chromosomal
Down syndrome 915 27.1 25.4 - 28.9 251 7.5 6.6 - 8.5
Trisomy 18 247 7.3 6.4 - 8.3 16 0.5 0.2 - 0.7
Trisomy 13 95 2.8 2.3 - 3.4 12 0.4 0.2 - 0.6
Note a dash (-) indicates data not available or not provided

Program Comment

The program leads provide their insights on data, operations, and recent achievements. Their interpretation of the data is particularly valuable because of their local experience and knowledge.

In 2015-2020 the number of births has decreased but prevalences have remained stable. Data collection method has remained unchanged. Data access for some conditions has become easier thanks to access to electronic health data. In 2010, the registry raised an alarm to the health authorities about three cases in the same small area of transverse limb deficiencies involving one upper limb (isolated transverse upper limb reduction defect). The general prevalence of this conditions is approximately one case in 10,000 births. In the following years, more infants were born with the same malformation in the same area of the Ain department. REMERA investigated this event and identified a cluster of eight cases of such a diagnosis, which the program is still investigating.


Down syndrome (trisomy 21)

By far the most common chromosomal anomaly, Down syndrome is known to occur more frequently (has a higher risk of occurrence) in births of women with higher maternal age

This pattern is universally observed, provided there is no significant bias toward missing pregnancies with Down syndrome in older women (e.g., because of unreported pregnancy terminations)

Down syndrome, overall and by maternal age

separately for all births and livebirths, prevalence per 10,000 (Poisson exact confidence intervals)
France REMERA, 2015-2020

All cases Livebirths

Cases

Prev 95% CI

Cases

Prev 95% CI
All maternal ages 915 27.1 25.4 - 28.9 251 7.5 6.6 - 8.5
< 20 years 4 9.8 2.7 - 25.0 2 4.9 0.6 - 17.6
20 to 24 34 9.7 6.8 - 13.6 14 4.0 1.9 - 6.1
25 to 29 89 8.6 6.9 - 10.6 26 2.5 1.5 - 3.5
30 to 34 182 15.2 13.1 - 17.6 48 4.0 2.9 - 5.1
35 to 39 310 50.8 45.3 - 56.8 71 11.6 8.9 - 14.3
40 to 44 265 199.0 175.8 - 224.5 67 50.3 38.3 - 62.3
45+ years 17 199.8 116.4 - 319.8 10 117.5 45.1 - 189.9
Age unspec. 14 - - 13 - -
Age unspec. = maternal age unknown or unspecified

Down syndrome - maternal age pyramid

Because of the relation between prevalence of Down syndrome and maternal age, the maternal age distribution in the population is a major determinant of the number of conceptions with Down syndrome in the population.

For programs that have maternal age specific data, one can compare the maternal-age ‘pyramid’ for all births in the population with that of births with Down syndrome. Typically, the distribution is skewed, with a relative excess of births with Down syndrome among the more advanced maternal age groups.

Down syndrome - birth rates matter

Despite the considerably higher risk (rates) of Down syndrome in mothers over 40 or 45 years, these age groups contribute comparatively fewer affected births than younger age groups. This is because birth rates matter: fewer births in the more advanced age groups mean fewer cases overall from those age groups.

A Pareto chart helps highlight the cumulative contribution of different age groups to the total number of cases. This information can help inform strategies for testing and counseling.

Linking risk factor profile and congenital anomalies

The term triple surveillance refers to a model of public health surveillance that births includes the full causal chain, from a) risk factors, which influence the number of affected pregnancies; to b) the affected pregnancies themselves, that are vulnerable to adverse health outcomes; and to c) the health outcomes in affected individuals. The burden of risk becomes expressed eventually in the burden of disease.

Historically, birth defect surveillance has focused on the second element, the occurrence of congenital anomalies.

However, improving outcomes (morbidity, mortality, disability) requires understanding and tracking risk factors (to improve primary prevention) and health outcomes (to improve care). Triple surveillance advocates integrating the tracking of all three elements in this causal chain. Together, these three domains provide clinicians, public health professionals, and policy makers with information to act.

To highlight such context, the next sections provide elements of country demographics, outcomes (mainly early mortality), and selected risk factors. These data, particularly those on risk factors and outcomes, are sometimes directly measured, and sometimes estimated. Birth defect programs with their partners can supplement these data with local assessments.

Country demographics

A surveillance program operates within its country’s demographic situation and trends. This information adds meaning and context to birth defect surveillance information.

Demographic Indicators, France

on population, births, life expectancy
Key Indicator 2022 data
Total population 67,971,311
Number of births 720,496
Birth rate (per 1000 pop) 10.6
Fertility (births per woman) 1.8
Life expectancy at birth (years) 82.2
Source: World Bank (accessed Sept 2024)

From program to country

Many (though not all) programs cover a proportion of the country in which they operate. In this setting, a common question is what the program can tell use about the impact of congenital anomalies country-wide, under the assumption that the program information is a good estimator for the country itself. This assumption, of course, needs to be carefully examined, and the program staff typically has the local knowledge to help frame such estimates within the strengths and limitations of the data.

The table below uses the prevalence measured within the program to estimate the number of births with selected congenital anomalies for the entire country. These extrapolations have limitations, and in most cases are illustrative. However, at times a program that covers a proportion of the population may be the only practical window into congenital anomalies country-wide.

A window into the country: France, 2022 estimates

Country-wide estimates for selected conditions (720,496 births), extrapolating from program data

All cases liveborn % liveborn
Neural tube defects (NTD)
Neural tube defects, total 901 160
Spina bifida 438 110
Anencephaly 327 11
Encephalocele 137 39
Other brain
Hydrocephaly 496 259
Microcephaly 167 112
Holoprosencephaly 154 11
Eye and Ear
Microphthalmos 130 82
Anotia 88 76
Microtia 68 58
Anophthalmos 11 2
Orofacial
Cleft lip with or without cleft palate 613 484
Cleft palate without cleft lip 496 393
Choanal atresia bilateral 49 43
Heart
Transposition of great vessels 318 251
Coarctation of aorta 254 242
Hypoplastic left heart syndrome 241 80
Tetralogy of Fallot 237 166
Gastrointestinal
Anorectal atresia/stenosis 256 177
Esophageal atresia 220 190
Small intestinal atresia/stenosis 70 63
Genitourinary
Undescended testis 1468 1484
Cystic kidney 803 568
Hypospadias 771 756
Renal agenesis 85 32
Indeterminate sex 23 17
Bladder exstrophy 21 4
Epispadias 15 15
Limb
Limb deficiency (LD), total 521 343
Polydactyly preaxial 239 229
LD transverse 179 112
LD postaxial 109 76
LD preaxial 83 58
LD axial 58 48
LD mixed 53 24
LD intercalary 26 22
LD unspec. 13 4
Abdominal
Omphalocele 305 97
Diaphragmatic hernia 246 166
Gastroschisis 122 106
Chromosomal
Down syndrome 1955 542
Trisomy 18 528 35
Trisomy 13 203 26
Note: includes conditions with at least 5 estimated cases. Assumes that prevalence estimates from program are valid country-wide.

Outcomes - early mortality

The relative impact of congenital anomalies on early mortality (neonatal, infant, and under 5 years) tends to increase as infant mortality due to other causes falls. This pattern has been observed worldwide. These general indicators of early mortality are tracked regularly by public health agencies.

Mortality Indicators, France

Key Indicator 2022 data
Neonatal mortality (per 1000) 2.5
Infant mortality (per 1000) 3.3
Under 5 mortality (per 1000) 4.1
Source: World Bank, accessed Sept 2024

Outcomes - mortality with congenital anomalies

A more specific indicator (infant deaths due to congenital anomalies) is more challenging to document accurately. Missed diagnoses, especially of internal anomalies, can lead to massive underestimates, especially in settings where diagnoses rely only or mostly on an external exam. The table below summarizes data and estimates from systematic public sources. However, local assessments from birth defect surveillance program can help improve the quality of this key indicator.

Deaths due to birth defects, France

among infants (< 1 year old) and from first to fifth birthday
Age group Percent

Deaths
/ 100k pop

Infants 19.7
66.4
1 to < 5 yrs 7.2
0.9
Source: WHO mortality data 2020 (who.int)

Risk factors

Some modifiable exposures are well-established risk factors for congenital anomalies. Reducing these exposures is the basis for effective primary prevention. Here we focus specifically on smoking, diabetes, and folate insufficiency. These factors, both common and modifiable, increase the risk of major contributors to morbidity and mortality, including orofacial clefts, neural tube defects, and serious congenital heart disease. The impact of these risk factors depend on their frequency in the population. The following tables show frequency estimates for the country. In another section, these data are used to estimate the number of cases in the country potentially preventable by eliminating the risk factors.

Smoking

Smoking is associated with increased risk for many adverse pregnancy outcomes and several congenital anomalies, including orofacial clefts and probably congenital heart disease. The increased risk is relatively modest (odds ratios tipically less than 1.5) but the effect size, or number of cases due to smoking, depends on the rate of smoking among women who become pregnant. Here we used country-specific estimates of smoking in women of reproductive age (see table for references). Rates of smoking during pregnancy tend to be lower, but by the time many women know they are pregnant, the at-risk period for congenital anomalies has often already passed.

Smoking in women

Frequency in two different groups, France
Women Frequency (%)
Of reproductive age 29.3 ( 25.3 - 33.7 )
During pregnancy 19.7 ( 15.6 - 24.0 )
Source: IHME | www.healthdata.org | and Lange 2018

Diabetes

Maternal pregestational diabetes is associated with increased risk for many serious congenital anomalies, including spina bifida, several critical congenital heart defects, and multiple congenital anomalies, among others. In some cases the relative risk (or odds ratio) can be quite high, above 4 or 5 in some cases. The effect size (number of cases due to diabetes) depends on the frequency of diabetes, which tipically increases with age.

Diabetes in women

Frequency by age group, France
Age Group Percent
15 to 19 0.2
20 to 24 0.3
25 to 29 0.3
30 to 34 0.5
35 to 39 1.0
40 to 44 1.7
45 to 49 2.6
Source: IHME | www.healthdata.org

Folate insufficiency

Folate insufficiency is associated with increased risk for neural tube defects and perhaps other congenital anomalies. On a population-basis, well-implemented folic acid fortification is estimated to decrease the prevalence of neural tube defects below 6 per 10,000 or perhaps even lower. Folic acid fortification is most effective when it is mandatory and universal, meaning that it involves foods commonly consumed by large parts of the population (e.g., wheat, maize, rice, depending on culture and geography).

Folic acid fortification

Status of mandatory fortification in France
Mandatory Food vehicle Year started
No - -
Source: FFI | fortificationdata.org

What if - prevention scenarios

What follows is a tricky but important exercise. By combining information about risk factors and prevalence of congenital anomalies, one can attempt to estimate the number of cases attributable to risk factors. This is illustrated in the table below, which uses prevalence information from the program and risk factor information (e.g., diabetes frequency in women) from country data. These estimates also require knowing the relative risk of disease given the exposure. Here we use odds ratios derived from high quality studies and metanalyses. These data then are fed into the Miettinen estimator of attributable fraction to generate the scenarios that you in the table.

Attributable cases for selected risk factors

yearly estimates in program and in country, and per million births
France REMERA, 2015-2020

Prevalence
per 10,000

attributable cases Risk factor parameters

Program

Country

per 1M births

Neural tube defects (NTD)
Neural tube defects, total 12.5 37 468 650 Presumed folate insufficiency, prevalence > 6
Orofacial
Cleft lip with or without cleft palate 8.5 4 55 77 smoking, freq: 29.3%, OR: 1.34
Cleft palate without cleft lip 6.9 2 30 42 smoking, freq: 29.3%, OR: 1.22
Heart
Transposition of great vessels 4.4 0 2 3 diabetes, freq: 0.3%, OR: 3.34
Hypoplastic left heart syndrome 3.4 0 3 4 diabetes, freq: 0.3%, OR: 4.58
Tetralogy of Fallot 3.3 0 3 4 diabetes, freq: 0.3%, OR: 4.89
Odds ratios from literature, exposure frequencies from country estimates (see methods for details). NTD estimates only where ETOPFA are included or not legally allowed. See text for details.

Arguably, these estimates are simplistic. For one, they assume accurate inputs. For neural tube defects, they assume accurate prevalence, including of stillbirths and pregnancy terminations. On the exposure side, e.g., for smoking and diabetes, they assume that the rates in women are accurate and reflect the true exposure rate in the periconceptional period (or at risk period). Moreover, the estimates are generated ‘one at the the time’ and do not account for multiple exposures (e.g., diabetes plus smoking) or interactions among multiple exposures. And so on. Nevertheless, even rough estimates provide an important message. Some instances, perhaps many, of major and even lethal congenital anomalies are preventable by reducing the burden of risk in populations and individuals. And in the examples provided (smoking and diabetes in particular), the benefits extend beyond the prevention of congenital anomalies to the prevention of many other health conditions, for the fetus as well as for the parents..